Tire curing rim structure



July 24, 1951 N. G. HOVLID r:r:u 2,561,573

TIRE CURING RIM STRUCTURE Filed Dec. 8, 1947 2 Sheets-Sheet l as W" NORMAN G. HOVL i0 GEOR E. B. BREA KEY July 24, 1951 N. s; HOVL ID t-rrAL TIRE CURING RIM STRUCTURE 2 Sheets-Sheet 2 Filed Dec. 8. 1947 N RMA/v How. i0 GEORGE E. BREA/(EY alto anew Patented July 24, 195

Norman G. Hovlid, Torrance, and George B.

Breakey, Los Angeles, Calif, assignors to American Tire Machinery; Inc., Muncie, Ind., a corporation of California Application. December 8, 1947, Serial No. 790,378

The present invention relates to vulcanizingl apparatus and more specifically to apparatus useiul in retreading worn pneumatic tires. It has been customary in retreading tires of different widths to utilize a different inside collapsible rim structure corresponding to each different Width of pneumatic tires whereby the inner conventional air bag is properly pressed against the tire and the tire is properly pressed against the conventional matrix. IWhere in accordance with such practice, it is necessary to stock many different sized curing rims for-satisfactory operation in a plant arranged for re treading tires of all widths. Consequently, the invested capital in the plant is relatively large and adequate storage space must be rcvidedfor" F the difierent rim structures. Usually, when such prior art rim structures are used in Lretreading tiresof sizesdiiferent from which they wereide signed for, objectionably large forces are exerted, on the rim structure to deform it inan obiectionable manner. This is partiallysosince the inner extending ends of such rim structure upon which a relatively large pressure is exerted by the airbag are supported as a cantilever.

It is therefore an object of the present inven tion to provide an improved collapsible curing rim structure which is useful in retreading tires of many diiferent sizes, a feature of the rim structure being that the rim structure, is self adjusting to accommodate itself for its intended purpose.

Another object of the present invention is to provide an improved self-adjusting rim structure which is of light weight, and fully collapsible. Still another object of the present invention is to provide an improved tire curing rim structure having two halves which is self-adjusting to serve efliciently for its intended purpose and which may be easily and quickly mounted and dismounted with relationship to the associated air bag and tire.

Yet another object of the present invention is to provide an improved self-adjusting tire cur ing rim structure.

Yet a, further object of the present invention is to provide an improved'tire curing rim structure made in separate halves, each'half having equal arched segments arranged so that it may either be self-supporting or solely collapsed very easily in a minimum amount of time.

Yet a further object of the present invention is to provide an improved tire curing rim structure having separate halves arranged forinde- 6 Claims, (CI. 18-18) duce the likelihood of objectionable deformation pendent movement in the direction of the axis of a tire with improved means interposed betweensuch separate halves which engages the" air bag properly regardless of the positions of such halves. Yet a further object of the present invention is to provide an improved tire curing rim structure wherein forces exerted on the rim structure by the inflated air bag are transferred to the mold structure in an improved manner to reof such rim structure which would otherwise be produced as if, for example, the inward extending ends of such rim structure were supported as a cantilever.

thereon by the bag to positions wherein forces are transferred from the bag to the outside mold structure whereby the likelihood of deformation of such rim structure is greatly reduced.

Yet a further object of the present invention is to provide an improved tire curing rim structure which is light weight, fully collapsible and fully adjustable in width and which may be used" with air bags of different cross-sections in relationship to the cross-section of the encircling tire arranged in position forretreading.

The features of the present invention which are believed to be novel are set forth with particularity in the appended claims. This invenvention itself, both as to its organization and manner of operation, together with further objects and advantages thereof, may be best understood by reference to the following descrip tion taken in connection with the accompany ing drawings in which:

Figure 1 is a cross-sectional view through av mold with a tire therein for a retreading operaembody tion using the apparatus shown therein ing the present invention.

Figure 2 is a sectional view taken substantially on the line 2-2 of Figure 1 showing only the tire curing rimjstructure" embodying the present invention.

Figure 3 is a view taken substantially in the direction indicated by the line 3-3 in Figure 2.

1 Figure is a perspective view showing in en,

larged form the normally abutting ends, of a por-' tion of the rim structure separated one from the other.

Figure 5 is a view in side elevation of the tire curing rim structure embodying the present in 3 vention, partly fragmented and with the rim structure in fully expanded position.

Figure 6 is a view in side elevation of one of the rim halves shown-in Figure in fully collapsed condition.

Figuresfl and :8 :are sectional views taken: re

spectively on lines I1 and 8--8 of Figure 5.

Figure 9 is a sectional view taken substantially on the line 9-9 of Figure 8.

In the assembly shown in Figure 1, a tire casing [0 in a range of sizes is disposed within a conventional tire of two-part mold l1, His-within which are recessed, respectively,;matrices-l3 and:

I4 and through which heating; fluid suchzaslx steam, passes through corresponding conduits l5,

upper matrix I3 may be free to move within its;

upper mold half 1 I.

I I6 therein. The lower matrix M maybe secured to the lower mold half l2 by bolts l8 while the" 4 v composite rim structure is self-adjustable as to width, or in the vertical direction in Figure 1. These two relatively movable rim halves 25, 26 are normally spaced from one another bythe air space 30 and for that reason the steel strap 28 bridging-such halves 25,='--j26;-is aprovided -to firmly .jstrip'itogserve as :a'combination guide and retaining member for the other V-shaped end 28B. Itis apparent from. the disclosure in Figure 4.-

' that'the. steel band 28 may thus be curved to form Structural features of the ,mold vI 1,1 [Lands matrices l3 and 14 may take different formsfand shapes as isawellzunderstood inthis art. and-.for.

example; the presentunvention may likewise be embodied in either a permanent moldlconstruc-I 1 tiorr; wherein the" matrices-are engraved inathe casting of theheaters similar-to heaters A l,\l2

onthe matrices l 3, It may likewise beremovablypositioned-inmolds of asingle heater type.

Further,.-in accordancewith conventionalprace tice;a= the--tire lU is'pressed against the ma-trices l3; M by the airbag :20' which likewise may take di-fiferentrforms and shapes andas shownlherein, hasra cross-section made up of two ovalshaped halves 26A, 26B of different curvature joined latadjacent ends at 20C, 20D in closezproximity to aqvertical line 21' drawnithrough-vthe'center-pf thetire III." The tire rimstructureembodylng-impjortant features of' the-present invention-is arranged tocontact the arcuate oval'shapede-por tion 20B of the bag and-is pressedinsideethe truck tire between the two adjacent annulanbeads;

23, 24 of the tire to'maintainthe inflated tube-20 during the rubber curing-interval Thiscuring rim comprises three elementsan uppepannular collapsible ring-25 and an adjacent similar an-' nular ring 26:,the spacing between the-members- 25 and 26 being bridged by'theythirdrnemberi which is aspring, steel band-28 recessed-sin; adsparts- :cfthe: members: 2 5 and 2 Si: A characterizing feature of the compositewcur-v ing.=rim structure 25,16; 28-; as described-sinzmore detaiLlatergis'that eachone ofthe two ringst25;

have pivoted'segments to'render them rfully' collapsible for quick-and convenient insertion andremoval" of the rim *structure-rfrcm in and from. within-the tire .I ll.

' Rings 25, 26 have respectively radiallyouter ends-25A; 26A"terminating"at :the bag portions 20 on the one hand and the corresponding matrix l3,'-l4 on the other hand withrthecarcass-of the? tire interposedbetween such matrices and; such? ends- 25A, 26A,in which casethere is substantially novunbalanced force upon such ends,25A,, -26A tendingto; deform them whichuwould otherwise 7 be the caseif the rim halves 25, Ziiwerejoined; together; thereby makingsuch endsZ 5A,..l2 6A, free, ends of a cantilever structure.

Thus, since suchends, 25A,,,26A ,are;1relative1y I moyablaithereis aminimum oinnbalanced tomes on such ends and of greater importance, the

rings of adjustable diameter with the V-shaped end 28B cooperating,, with, the veshaped notch 28,A ,to. .maintain the ,abutting ends. vof ..the. strip, 28" in aligned (position, and with the member, 286; welded-thereonretaining the vend 28B .frommoying outwardly. This strip "23, as showniinrFigure 5,;is aperturednat -28E',for the, passage vvtheree throughof the conventionalvalve stem-on bag-2G,?

Eachrim hali,25, 26 comprises .eightarchedlseg ments, 25E,.1 25E ,with adjacent. ends thereof,

pivotally connected .oncorresponding pinsv 35;};

extending invthe manner vshown in Figures 8 ,and 9." .Pin 36 extendshthrough.andjoins thegroove defining members 38, 391.011 one memberZBRW-itlu the, tongue member m lon the adjacent member-i 26E, the pin 36., being prevented from ,moving -in; its-v longitudinaldirectionby a tfastening spin -.4 2

' passing through.agroove ,inpin 35:-with the ends:

of, '.the, retaining,, pin (42 frictionally held, in.,the.- trial ,hole' 44 -in,.tongue member -40. These ree taming, pins "42. may. be driven -,out--,of the-otria1l holes, if ,desiredto. remove,them.iwherebmthe= pin',36,mayin-turn,,be removed toallowadjacent;

segmentslfiEto beidisconnected. As. shown in ,Figure. .5,,the' inner wall portion. of rim halves 25,. 25" are curvedias indicated-at 25G .to allow passage therethrough.-;of,-.;the valve stemof the-bagiil. Theseclearance-grooves 25G; and the corresponding clearance groove (not: shownxiinnrimahalf, 26, aresol disposed tliatthe pinsfiii 31 respectively joining-the segments (ofia, rim ,half 25,526,. are staggered therebyl, giving greater strength to the composite hingedfstruc-a ture,

It..is apparent. that. the apparatusdisclosed;-is; Well adaptedto accommodate itires of avary-i-ng-p sizes, there being some adjustment providedcbyr the. -annular. spacers a l uiwhich mayr-be-l of :variables-thickness, andsby i the sel-fadjusting-,- teas; ture of the. rim structure 25,15,25 and,28.- Thus;

' if a largentireithanlthat one shownr in Figs;

ure, 1 ,is, to, be ,retreaded, 4 the particularyspacer: 141i ,shown therein ,isl'removed and, aspaces: of greater thickness is inserted betweenzlthel-lmatwa flees-13mm; In,such..case, when theibag 20:15 properlyiinflatedlto its, prescribed pressure-, the; rim halves Z5, 26 are moved about to-againlconv tact, the .innermwall ofithe tire .which we' hava-as- I sumed to-be ,ofwlarger-widtht Preferably, as shown, in, Figures 7 =and--8, thei ends 25A, 2fiA;0f -,rim ,halves 25,125 have flatysuns faces 2 5E land .2611, respectively thereon to teens:

tact the inner, side wall. on, an: extending areal thereby. minimizing ,the, likelihood of ,damagesto the/inner, ,tire wall. It is .lapparenti that ,the rim, structure isiadaptabla-for usewith be et Eleni} different cross-sectional configurations. For example, the joining portions ZilC and 20D may be further to the left or right in Figure l in which case the ends of the rim halves '25, 25 wiil extend further inwardly or outwardly out of the tire as the case may be.

In order to facilitate removal of the tire after a curing operation when such tire tends to remain stuck in the matrix, there are preferably two extractor lugs (not shown), one each on upper rim half 25 and on lower rim half 25 which may be apertured for the insertion therethrough of a lifting hook, inaccordance with conventional practice.

While the particular embodiments of the pro ent invention have been shown and described, it will be obvious to those skilled in the art that changes and modifications may be made without departing from this invention in its broader aspects and, therefore, the aim in the appended claims is to cover all such changes and modifications as fall within the true spirit and scope of this invention.

We claim:

1. In a tire retreading apparatus, a tire curing rim structure comprising a pair of collapsible rim structures, each structure comprising a plurality of pivoted segments arranged for disposition within a tire for movement with respect to one another during the time heat is being applied to the tire in the tire retreading operation, each structure being grooved on its outer periphery so as to define together a single recess, a flexible strip floatingly mounted within said recess for bridging the gap between the struce tures when they are separated, said strip extending around the entire circumference of both of said rim structures and having freely movable complementary circumferential ends.

2. In apparatus of the character described, a

tire curing rim structure comprising a pair of collapsible rim structures, each pair comprising a plurality of pivoted segments movable to adjusted positions in accordance with the width of a tire during the time heat is being applied to the tire in the tire retreading operation, each structure being grooved on its outer periphery so as to define together a single recess, a flexible strip floatingly mounted within said recess for bridging the gap between the structures when they are separated.

3. In apparatus of the character described, a tire curing rim structure comprising a pair of collapsible ring structures, each comprising a plurality of pivoted segments mounted for pivotal movement on pivot pins, said pair of ring structures each having a cooperating groove to allow the passage therethrough of a valve stem, the axes of the pivot pins of one of said pair of ring structures being displaced with respect to the axes of the pivot pins of the other ring structure when said cooperating grooves are positioned for the passage of a valve stem therethrough.

4. In apparatus of the character described wherein an inner air bag is used to press a tire against an outer matrix, a tire curing rim structure comprising a pair of collapsible ring struc 'tures relatively movable with respect to one another to adjust themselves for tires of different widths, the radially outer end of each one of said pair of ring structures being sufficiently long to extend midway up into the tire to a position between said air bag and said outer matrix, and being adapted to contact the inner wall of said tire on an extended area so that such radially outer ends tend to be compressed beaway from one another under the influence of the compression forces exerted by said bag on said outer ends to redistribute stresses such as to further minimize the presence of such cantilever forces, each ring structure being grooved on its outer periphery so as to define together a single recess, and a flexible strip fioatingly mounted within said recess for bridging the gap between the ring structures when they are separated.

5. In apparatus of the character described, a tire curing rim structure comprising a pair of collapsible ring structures, each ring structure comprising a plurality of pivoted segments, each ringstructure being grooved on its outer periphery so as to define together a single recess, a flexible strip floatingly mounted within, said recess for bridging the gap between the ring structures when they are separated, said flexible strip having its complementary circumferential ends respectively terminating in a \l-shapedl notch a cooperating ll-shaped projection.

6. In apparatus of the character described, an annular heater, a spacer, a matrix comprising two separate halves mounted within said heater and maintained in adjusted position with respect to one another by said spacer of predetermined thickness disposed between said matrix halves,

and a collapsible rim structure comprising a plurality of pivoted sections arranged for disposition within a tire accommodated by said matrix halves so spaced, said rim structure comprising a pair of collapsible ring structures adapted for relative movement with respect to one another during the time when heat is being applied to the tire in the tire curing operation to automatically adjust themselves for tires of dif ferent widths, each ring structure being grooved on its outer periphery so as to define together a single recess, a flexible strip floatingly mounted within said recess for bridging the gap between the structures when they are separated, said strip extending around the entire circumference of both of said ring structures and having freely movable complementary circumferential ends.

NORMAN G. HOVLID. GEORGE E. BREAKEY.

REFERENCES CITED The following references are of record in the file of this'patent:

UNITED STATES PATENTS Number Name Date 1,579,518 Connelly Apr. 6, 1926 1,643,493 Gregg Sept. 27, 1927 1,703,970 Thorsen -l Mar. 5, 1929 1,786,291 Denmire Dec. 23, 1930 2,372,246 Bacon, Jr Mar. 27, 1945 2,513,482, Heintz July 4, 1950 

